How To Make Your Iguana Grow Faster?

Many iguana owners want their iguanas to grow healthy, and… Big. Iguanas have a different growth rate, and some owners are often asking, “Why is my iguana so small?”. There are many factors that affect the growing rate of your iguana. In this post, we will discuss how to make your iguana grow faster, iguana growth chart and what factors affect the growth of your iguana.

How long do iguanas grow?

Iguanas can take as long as 4-7 years to grow to full size. This will depend on many things, such as genetics, environment that iguana lived in and food it was eating. Iguanas will grow very quickly during the first 3-5 years, and after that – the growth slows down a lot.

If the iguana is healthy, you can predict its age. But if you don’t know anything about iguana’s past, then you shouldn’t predict its age. Also, don’t fully trust someone that claims to know iguana’s age judging only by its size.

If an iguana lived in bad conditions, it can be much smaller than most other iguanas. Bad sellers can claim that iguana is young, while in reality it is much older but is not in the best health.

Generally speaking, if you keep your iguana in very good conditions, it will not grow bigger than it’s supposed to (genetics). But if you keep it in bad conditions, it will not reach its maximum size. Some types of iguanas get bigger because of their genetics (especially iguanas from South America).

Also, some iguanas might stop growing for few months at a time. This is normal, but can also be caused due to different reasons. After this period, your iguana will start growing again at a faster rate.

Iguana size chart

You can see quite big ranges for iguana sizes. An adult male iguana will be much bigger than a female. A full grown iguana male can reach 5-6.5 and even 7 feet (152-213 cm).

However, females often do not get bigger than 4.5 feet (around 137 cm). But most male iguanas in captivity never reach 7 feet long. These sizes are body + tail length (STL).

You can also see that the difference between the sizes increases with age. This is because your iguana will be growing actively during the first 1-4 years, and this is the crucial time for growth. A 1 year old iguana can already reach 18-27 inches in full length an weigh 500-600 grams.

Bad conditions, poor feeding and other factors can have a life-long effect on iguana’s size. In this chart, the lower range will be more suited to female iguanas, and the highest range – to males. These numbers are only approximate and iguana’s size will greatly depend on both lineage and environmental factors.

Iguana growth rates

During the first 3 months, your iguana can grow 0.09-0.2 cm (0.035-0.078 inches) per day. This can equal to around 1-3 inches per month, or around 2.5-7 cm. This is provided your iguana lives in good conditions and eats high quality staple foods.

How to make my iguana grow faster?

There are many factors that will determine the size and growth speed of your iguana. If your iguana has been living in bad (or below average) conditions for a year or more, then it will not grow to its maximum size.

This is because the growth slows down after few years of iguana’s life. That is why iguanas need to be taken care of especially greatly during its first 3-5 years if you want it to grow large.

Tip #1: Make sure that the cage is big enough

While cage size doesn’t directly affect iguana’s size, your iguana is not likely to grow big if you keep it in a small cage. The cage size does indeed greatly affect your iguana’s size.

Iguana’s cage must be much bigger than the iguana itself, to let it move around. The cage for an iguana must also be vertical in shape, because iguanas spend most of their time basking on branches. Above the basking spot you should setup UVB and heating lights for your iguana.

While you shouldn’t keep your small iguana in a big cage, there is no limit in cage size for an adult iguana. Also, make sure to keep all iguanas separately (at least from 6 months old).

The best thing to do is to have a smaller cage for your iguana to live in for around 2 years, and then switch to a permanent cage that your iguana will live in for the rest of its life.

This way your iguana won’t be overwhelmed in a big cage as a baby, and then a smooth transition to a big cage will promote interest and growth. Many owners have stated the increase in iguana’s growth after switching to a bigger cage.

• One of the best options for an iguana cage for around 1-2 years is this Reptibreeze IguAnarium by Zoo Med. This terrarium is 36″ x 18″ x 48″ (90 cm x 45cm x 120cm) in L x D x H. This cage will be suitable for your iguana for around 2 years.
• Another terrarium option for a hatchling iguana to up to 6 months-1 year – a large tall 36”x 18”x 24” tank by Exo Terra like this. This tank is 67 gallons in size and is perfect for the first year of iguana’s life.
• If your iguana is very small (hatchling), you can even start out with a 40 gallon tank and switch in few months. But this will cost you extra money and can be quite stressful for an iguana. It is a better idea to get a larger terrarium and then build a bigger one.
• After your iguana becomes too big for this terrarium, you will need to buy or build a custom cage. The cage for an adult iguana should be at least 1.5 times it length, 1.5 times in height, and be at least the same width as your iguana. This way, you will be able to accommodate ledges and place a basking branch.

Tip #2: Make sure to have proper UVB lighting in iguana’s cage

Without the proper UVB lighting your iguana will develop vitamin D3 deficiency. Vitamin D3 is essential for calcium metabolism, too. Without calcium and vitamin D3, iguana can develop deficiency, and Metabolic Bone Disease. Iguanas bask a lot in the wild, and you must setup UVB lighting in iguana’s cage.

Calcium deficiency will not only impair iguana’s growth, but also make the bones soft and fragile. The effects or MBD are often hard to reverse and improve. It will also take time to treat, wasting the time when your iguana could be growing.

You can find a post on iguana lighting and heating in this post.

Tip #3: Supplement your iguana’s food

Along with UVB lamps, your iguana needs a big range of other vitamins and minerals to thrive and grow. Calcium and vitamin D3 are not the only mineral and vitamin that your iguana needs.

Make sure to sprinkle iguana’s food with supplements accordingly. But also be careful not to use too much – vitamin toxicity also has very negative consequences.

Some reptile supplement products contain too much vitamin D3 in them (3x-10x times higher the recommended dosage), which can lead to toxicity over time. The best way to supplement your iguana’s food is to:

• Never give your iguana calcium with vitamin D3. Iguanas need to synthesize their vitamin D3 when exposed to UVB lights and unfiltered sunlight. Vitamin D3 can only be present in optimal doses in multivitamins.
• Giving your iguana any vitamin D3 supplement can be risky. This is because iguanas get a lot of exposure to the lights (they must do). Vitamin D3 in a powder form can be left unused by the body and cause toxicity. Do not choose vitamin D3 supplements that have more than 45,000-50,000 IU/kg of vitamin D3.
• Always make sure to buy pure calcium separately, and then a multivitamin only. This way you will minimize any risks of over-supplementing your iguana.
• One of the good pure calcium supplements is this ReptiCalcium by Zoo Med that is pure calcium carbonate. Do not choose calcium lactate.
• A good multivitamin is this Rep-Cal multivitamin complex that contains a balanced Ca:P ratio and a set of minerals, vitamins and amino acids. There is no vitamin D3 in this supplement.
• If you believe that your iguana really needs some vitamin D3, it can be included in a multivitamin. Or, you can get a small jar of calcium + vitamin D3 and only use that one once a week.
• Sprinkle your hatchling iguana’s food with calcium once a day, baby’s food – 4 times a week, and adult’s food – once a week. Then, sprinkle gravid iguana’s food with calcium every other day.
• Use one pinch to supplement food for hatchlings and babies, and for adults – one pinch per a kg of weight.
• Sprinkle your iguana’s food with multivitamins once a week for babies, and once in 2 weeks for adults.

If you would like more information on supplementing iguana’s food, read this post.

Tip #4: Feed your iguana best staple foods

Simple as it might seem, if you don’t feed your iguana nutritious staple foods, it won’t grow well. Don’t feed your iguana too many fruits (10% of the diet only), foods high in oxalic acid or goitrogenic foods. These types of food will interfere with vitamin and mineral absorption.

Instead, feed staple foods that are high in nutrients and have a good Calcium:Phosphorus ratio. Make sure to offer at least 3 staple foods to your iguana every day (for example turnip, collard and mustard greens, dandelion).

Find the list of best plants, greens, veggies and fruits for your iguana in this post.

Tip #5: Let it exercise and move around

We all know that iguanas are not the most active lizards. Iguanas tend to get less and less active with age. But while your iguana is growing, you need to promote activity by letting it roam the room or letting it walk in the garden.

Put a leash on your iguana if there is a chance of escape. Create climbing spots, ramps and so on for your iguana to move around.

More your iguana moves around, hungrier it will be. Moving around will build a stronger body and eating more food (more staples please) will help the body grow.

Feed your iguana 2-3 times a day while it is young. Iguanas can eat as much as they like – they are unlikely to gain weight and become fat. But never force feed – it will make your iguana sick.

Tip #6: Do not offer your iguana animal protein, dog food or eggs.

Many dishonest sellers and breeders used to (and some still do!) feed iguana lots of protein-rich foods during the first 6-12 months of its life to make it grow faster and bigger.

While this technique works, and iguanas fed on protein-rich foods do get big, they don’t live long lives. Most of these iguanas die of complications only few years after.

Never feed your iguana any insects such as crickets, dog or cat food, meat, fish or eggs to make your iguana bigger. Your iguana is strictly a vegetarian. It is better to grow slower, but live a longer life.

Feeding your iguana any meats and other high-protein foods will strain the kidneys, which will eventually fail much sooner than expected (after 5-6 years). Renal failure will cause painful death for your iguana.

Instead, feed your iguana vegetables that are higher in protein, to help it grow. These include green, lima, butter beans and so on. You should also limit the protein intake in iguana’s diet when it turns around 5 years old. This will reduce any strain on kidneys.